矢量网络分析仪误差模型及校正理论的研究

【作者】 侯政嘉；

【导师】 童玲；

【作者基本信息】 电子科技大学 ， 检测技术与自动化装置， 2005， 硕士

【摘要】 S 参数被广泛地用来表示微波网络的特性,微波S 参数及其测量是微波专业教学、科研和实验中的重要内容之一。随着计算机在微波领域的推广应用和微波电路计算机辅助设计(CAD)的不断发展,网络的S 参数成为微波CAD 的重要依据。因此,微波S 参数的精确测量以成为微波领域里所面临的重要课题和方向。矢量网络分析仪是测量S 参数的主要仪器,由于其测量系统存在的各种误差使测量值与真实值之间有一定的差距,所以矢量网络分析仪在对被测件进行正式测量之前,必须对测量系统进行校正,以消除系统测量误差。本文在详细分析矢量网络分析仪的结构、工作原理、信号流向、测量方法等的基础上,通过一定的理论计算和分析,建立新的8 校正误差模型,给出了OSL(OPEN+ SHORT+LOAD)和SLT(LOAD+THROUGH+SHORT)两种标准件校正方法,简化了测试校正计算,并通过实验予以验证。传统的校正方法是用仪器生产厂家提供的标准件(标准短路器、标准开路器、标准匹配负载)利用仪器的校正功能及其存储在仪器内部的标准件参数对测量系统的12 项误差进行校正测试。但是生产厂家提供的标准件都是同轴接头的,而在实际测量中,被测件的接头方式有多种多样。本文还介绍了利用校正件中比较容易实现的短路器,和一根反射和传输损耗相对较小的传输线取代标准校正件对12 项误差模型和8 项误差模型的两种校正方法。本文介绍的8 项误差校正模型减少计算工作量,提高测量速度。由此,使得测量结果更逼近器件的动态性能,满足实时测量要求。特别是军事电子测量领域,与传统误差校正原理相比,它更能满足高速、高精度的现场测量要求。对以后模块式“矢量网络分析仪”的发展具有重要的意义。而且非标准校正方法放弃了造价昂贵的标准件,利用容易实现的非标准校正件对测量系统进行校正,解决了大多数实际测量中的困难,对利用网络分析仪测量多种接头形式的被测件具有重要意义。更多还原

【Abstract】 S-parameters has been wildly used in describing characters of microwave network and is important part of teaching, researching and experiment in the microwave field and the development of CAD, S-parameters become the main basis of microwave CAD. Therefore, the precise measurement of S-parameters has developed to be main topic and direction encountered by microwave field and is a necessary tool in the teaching and research. The microwave network analyzer is main instrument to measure S-parameters. Because of all kinds of errors existing in the measurement system which could result in bias between measure value and the truth. In order to remove the system errors, the Vector Network Analyzer (or VNA) must be calibrated before measuring the devices under test. Based on detailed analysis on architecture, working principle, signal flowing directions as well as measurement methods of the VNAs, this article sets up the 8-Errors Module, introduces two error correction methods using standard calibration kits: the OSL (OPEN+ SHORT+LOAD) method and the SLT(LOAD+THROUGH+SHORT) method. We found that this module can simplify the calculation in calibration. And we validate it in our experiments. Traditional calibration methods are done by using standard kits (e.t. standard SHORT, OPEN, MATCH) provided by instrument manufactures, calibration function set in and standard kits data stored in instruments. However, manufactures always provide standard kits with coaxial ports, while the port types of devices under test varies. This article also introduces 12-errors-module and 8-errors-module nonstandard error correction methods using SHORT and transmission LINE as calibration kits. Usually, the calibration kits SHORT and transmission LINE can easily be realized in practical measurement situations. The error correction methods given in this article can cut down the calculation work and speed up the VNA measurements. For these reasons, the measurement result can get closer to the dynamic performances and satisfy real time measurement requirements. Compared to traditional calibration theories, the 8-Errors calibration can meet the demand of high speed and high precision field situation, especially in the realm of military electric measurement. This module can also be of great value to the modularization of the VNA in the future. The nonstandard calibration methods given in this article give up the expensive standard calibration kits and solve most related problems in measurement practices. This article is also of great value to measurement on devices with various port types.更多还原